Display devices such as a thin film transistor (TFT) liquid crystal display device and an organic electroluminescent (EL) element generally include an electrode protective film, a planarization film, an insulating film, and the like that are patterned. As a material to form these films, a photosensitive resin composition that gives a required pattern profile in fewer steps and achieves adequate flatness is conventionally and widely used instead of other photosensitive resin compositions.
As for fabrication of a display device, studies have been actively conducted in recent years on techniques of employing ink-jet printing to fabricate a substrate for full-color display. As for fabrication of a color filter for a liquid crystal display device, for example, suggestions have been made on a color filter obtained by, instead of employing conventional printing, electrodeposition, dyeing, or pigment dispersion, forming a patterned compartment (hereinafter, called a bank) for defining pixels with a light-shielding photosensitive resin layer, and then supplying ink dropwise into an opening surrounded by the bank, a method for fabricating the same (see Patent Document 1, for example), and the like. As for an organic EL display device, a method for fabricating an organic EL display device by forming a bank first and then supplying ink dropwise to form a light-emitting layer has been suggested (see Patent Document 2, for example).
In the case where ink-jet printing is employed to supply ink dropwise into an opening surrounded by a bank, the substrate must have an affinity with ink (hydrophilicity) and the bank must be water repellent on the surface thereof in order to prevent ink droplets from overflowing the bank into an adjacent pixel.
In order to achieve these objects, continuous plasma (ozone) treatment such as oxygen gas plasma treatment and fluorine gas plasma treatment has been suggested to give hydrophilicity to a substrate and water repellency to a bank (see Patent Document 3, for example). These processes of treatment are, however, complicated in the steps. Formulating a fluorine surfactant or a fluoropolymer in a photosensitive organic thin film has also been suggested (see Patent Document 4, for example), which is, however, impractical because this has many things to be considered including not only photosensitivity but also coating film properties such as the compatibility and the addition amount, and because the surface water repellency deteriorates due to UV/ozone treatment during hydrophilization treatment of the substrate.